Fuel pellet and method of producing fuel pellet

ABSTRACT

An ignitable combustible fuel pellet and a method for manufacturing an ignitable combustible fuel pellet are disclosed. The ingredients of the fuel pellet are ground shelled corn, an igniting agent for facilitating continued combustion of the fuel pellet, a bonding agent for bonding the ingredients together, and an anti-caking agent for promoting flowability of the ingredients during the manufacture of the food pellet. The method of forming the food pellet comprises the steps of grinding shelled corn in a hammer mill, mixing the shelled corn with the other ingredients in a grinding mill, and pressing the combined ingredients in a pellet mill.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provision patent application is a continuation ofnon-provisional U.S. patent application Ser. No. 11/682,933, filed Mar.7, 2007, and claims the benefit of that application and of U.S.Provisional Application No. 60/810,958, filed Jun. 5, 2006.

BACKGROUND

The energy and home heating industry are dominated presently by oil.With fossil fuel prices reaching unprecedented levels world wide, manyconsumers are turning to alternative fuel sources to heat their homes.Gas, wood and alternative energy are a growing segment of the industryas consumers search for heating methods that are both economical andgood for the environment. Manufactured fire logs and wood pellets forfireplaces and stoves are well known and widely used as a convenientheat source. In the recent past, pellets comprised of various cellulosicmaterials have emerged as an alternative fuel source for home heating.In Europe, where there is a significant push for environmentally safe,affordable fuel alternatives, the wood pellet has enjoyed overwhelmingpopularity. Despite the fact that the U.S. has been slow to catch on tothis trend, indications are that the use of wood pellets is growing.According to the Pellet Fuels Institute, sales in the U.S. of pelletstoves increased by 74 percent from 2004 to 2005. While being a positiveindicator for the industry, this increase spurred a nationwide pelletshortage. With much of the nation's wood pellet supply being shippedoverseas, producers were unable to meet the demand on home soil. Pricesof the pellets more than doubled and despite placing restrictions on thenumber of bags that could be purchased at one time, many retailers ranthrough new shipments in less than a day. Unable to get enough fuel toheat their homes, consumers were forced to resort to fossil fuels forthe remainder of the winter.

Moreover, the quality of the pellets has recently been in questionbecause of the addition of sub-grade materials and thermoplastics, whichtogether produce fewer BTUs, more emissions, soot and ash. Most woodpellets are made from compressed sawdust, which is a by-product in thefurniture making and other wood processing industries, and a wax orthermoplastic bonding agent. The addition of wax or thermoplastic in thepelleting process serves to bond the mixture together. However, whenburned, this bonding agent emits harmful and/or damaging chemicals andsoot into the environment.

Furthermore, new technologies are consuming more of the raw materialsused to make the pellets. Even though trees are a renewable, naturalresource, their slow maturation rate, combined with the nation'sthriving lumber trade, will continue to present challenges to the woodpellet industry. To meet the nation's growing need for clean,affordable, accessible heating sources, the U.S. must vigilantly pursueviable alternatives.

Information relevant to attempts to address these problems can be foundin U.S. Pat. Nos. 3,635,684, 4,236,897, 4,324,561, 4,529,407, 4,702,746,5,342,418, 5,393,310, 5,980,595, 6,113,662, 6,635,093, 6,793,697,6,811,759, and International Publication Numbers WO2004/015041 andWO2000/60030. However, each one of these references suffers from one ormore of the following disadvantages: (1) product contains athermoplastic bonding material, causing a less environmentally friendlyoutput as well as increased soot build-up and emissions, (2) product hasa lower overall heat output and (3) product is more expensive toproduce. U.S. Pat. No. 7,318,431 is directed to the construction andoperation a stove for combusting biomass materials to generate heat.However, while this patent broadly mentions some biomass materials thatcan be combusted in ground or pellet form in the stove, it is silent asto the details of the content and formation of fuel pellets that arecapable of accomplishing the advantages of the invention set forthherein.

For the foregoing reasons, there is a need for a more environmentalfriendly and efficient, cheaper and more readily available alternativefuel product that can ease the United States' dependency upon oil andsatisfy the deficiency in the pellet industry.

SUMMARY

This invention is directed to a fuel pellet that will satisfy the needfor a more environmental friendly and efficient, cheaper and morereadily available alternative fuel product that can ease the UnitedStates' dependency upon oil. The fuel pellet having features of thepresent invention comprises a mixture with a majority of ground shelledcorn, and further comprises a bonding agent, an igniting agent, and ananti-caking agent in certain mixtures. In an optional embodiment of theaforementioned fuel pellet, the corn may be comprised wholly of grade 2ground shelled corn having a moisture content of not more than about 15%by weight. As a further option, the bonding agent may be comprisedsolely, or in part, of soy hulls, milo, or any type of distiller grain,among other things. As an alternative option, the anti-caking agent maybe comprised solely, or in part, of pulverized limestone, dehydratedphosphorus, or crushed egg shells, among other things. As yet anotheroption, the igniting agent may be comprised solely, or in part, of wheatmidds, speltz, milo, or any type of dried distiller grain, among otherthings.

It is the object of this invention to: (1) provide an efficient, costeffective, environmentally friendly fuel source with low soot output, inthe form of a fuel pellet; (2) provide a fuel pellet containing a majorportion of ground, shelled corn; (3) provide a fuel pellet with a highheat output; and (4) promote the production and processing of corn inthe United States of America, and further support the farmers who growand process this crop.

Furthermore, this invention provides a method for the production of thisfuel pellet. This method is novel due to the novel use of ingredients inthe aforementioned composition. Generally, the method involves grindingshelled corn into a fine powder, mixing this with the other ingredientsand pressing them through a die to produce a novel, clean burningheating source ready for packaging and shipping. All shelled corn musthave a moisture content less than 15% to ensure proper bonding of theingredients, and to prevent caking during the grinding and pressingsteps.

DESCRIPTION OF THE DRAWINGS

The drawings presented hereafter are to be used together with thedescription and appended claims to explain the inventive aspects of theinvention, and representative examples of the embodiments herein. Thedrawings are not to be construed as limiting the invention to only theillustrated and described embodiments.

FIG. 1 is a graph showing a percentage range of ingredients in analternative embodiment of the invention, where the percent of theigniting agent is held constant;

FIG. 2 is a graph showing a percentage range of ingredients in analternative embodiment of the invention, where the percent of thebonding agent is held constant;

FIG. 3 is a graph showing a percentage range of ingredients in analternative embodiment of the invention, where the percent of theanti-caking agent is zero, and the percentages of the igniting agent andthe bonding agent are reduced proportionately as the percentage of cornis increased;

FIG. 4 is a graph showing a percentage range of ingredients in analternative embodiment of the invention, where the percent of theanti-caking agent is 5%, and the percentages of the igniting agent andthe bonding agent are reduced proportionately as the percentage of cornis increased; and

FIG. 5 is a block diagram that shows the method by which the inventionis produced.

DESCRIPTION

The present invention provides both a fuel pellet and a process for itsmanufacture. The fuel pellet herein provides a novel combination ofingredients to provide a cleaner burning, more environmentally friendlyfuel to be used in pellet stoves and/or corn stoves. This combination ofingredients is novel in that it uses ingredients from a list comprisedof shelled corn along with other commodity by-products never beforeintegrated to satisfy the overall goals of providing a mixture which iseasily produced, with low soot and high temperature output. Groundshelled corn is used as the primary ingredient to produce a high heatoutput when burned in a corn or pellet stove for home, office orindustrial heating. An igniting agent is added to the mix which enablesthe resulting pellet quickly combust when placed in a pellet or cornstove. A bonding agent is added to bond the material together, alongwith an anti-caking agent that promotes flowability when the material ispushed through the pellet die during production.

The reader's attention is directed to all papers and documents which arefiled concurrently with this specification and which are open to publicinspection with this specification, and the contents of all such papersand documents are incorporated herein by reference. All featuresdisclosed in this specification (including any accompanying claims,abstract or drawings) may be replaced by alternative features servingthe same, equivalent or similar purpose, unless expressly statedotherwise. Thus, unless expressly stated otherwise, each featuredisclosed is one example only of a generic series of equivalent orsimilar features.

The Fuel Pellet

DESCRIPTION-PREFERRED EMBODIMENT

The preferred embodiment and best mode specifies a particular ratio ofamounts of ingredients that will be passed through the method ofproduction as described below. Generally, this invention comprises fineground shelled corn as the primary heating source, a bonding agent, ananti-caking agent and an igniting agent. Specifically, and in the bestmode, the following relative amounts of ingredients should be used: 50%by weight grade 2 fine-ground shelled corn, 20% by weight soy hulls as abonding agent; 25% by weight wheat midds as an igniting agent, and 5%pulverized limestone as an anti-caking agent. The preferred moisturecontent of all ingredients must be less than or equal to 15%. Thisensures proper bonding of the ingredients and flowability of the mix asit is pressed through the pellet mill die.

DESCRIPTION-ALTERNATIVE EMBODIMENTS

Although the present invention has been described in considerable detailwith reference to a certain preferred version thereof, other versionsare possible. For example, Attached FIGS. 1-4 will be used to displaythe range of desired amounts of ingredients included in alternativeembodiments. The percentage of ground shelled corn can be increased fromaround 50% to around 75%. The remaining amounts of ingredients must beadjusted accordingly, and this is exhibited in FIGS. 1-4.

Furthermore, while the preferred anti-caking agent is pulverizedlimestone, alternatively, pulverized dehydrated phosphorus, or crushedegg shells may be used. Additionally, while the preferred igniting agentis wheat midds, alternatively speltz, milo, barley, oats or wheat may beused. Finally, while the preferred bonding agent is soy hulls,alternatively milo or any type of drier distiller grain may be used.

FIG. 1 represents an alternative embodiment whereby the percentage byweight of ground shelled corn is increased in a linear fashion fromabout 50% to about 75% 10. The percentage by weight of the ignitingagent is held constant at 25% 12, the percentage by weight of thebonding agent is thusly decreased from 20% to 0% 14 in a linear fashionrelative to the increase in ground shelled corn, and the percentage byweight of the anti-caking agent is adjusted accordingly 16. Thepercentage of ground shelled corn must not exceed approximately 75% byweight, doing so would cause the fuel pellet to become unstable in itsfinal state and potentially crumble apart.

FIG. 2 represents an alternative embodiment whereby the percentage byweight of ground shelled corn is increased in a linear fashion fromabout 50% to about 75% 18 as above. However, this embodiment maintainsthe percentage the bonding agent at 20% by weight 20. The percentage ofthe igniting agent is decreased in a linear fashion from around 25% to 022. The anti-caking agent will remain constant at around 5% 24.

Similarly, FIG. 3 represents an additional alternative embodimentwhereby the percentage by weight of ground shelled corn is increasedlinearly from about 50% to about 75% 26. In this embodiment, thepercentage by weight of both the igniting agent and the bonding agentare decreased proportionately and in a linear fashion from about 25% toabout 12.5% 28. The anti-caking agent is not included in this embodiment30.

FIG. 4 represents an alternative embodiment whereby the percentage byweight of ground shelled corn is increased in a linear fashion fromabout 50% to about 75% 34. Alternatively, this embodiment decreases thepercentage by weight for the igniting agent in a linear fashion fromabout 25% to about 12.5% 36. Furthermore, the percentage by weight ofthe bonding agent is decreased linearly from about 20% to about 7.5% 38,with the percentage by weight of the anti-caking agent being heldconstant at about 5% 40.

The previously described versions of the present invention have manyadvantages, including: high heat output, clean burning and low sootoutput and environmentally friendly. However, the invention does notrequire that all advantageous features and all the advantages need to beincorporated into every embodiment of the invention. Furthermore, thepresent invention has been described in considerable detail withreference to certain preferred versions thereof, other versions arepossible. Therefore, the spirit and scope of the appended claims shouldnot be limited to the description of the preferred versions containedherein.

The Method of Production

FIG. 5 shows the method of producing fuel pellet. All ingredients areinitially stored 42. Wheat midds, a preferred choice as an ignitingagent, are a by-product from the milling of wheat flour or durum as usedin pasta. Typically pressed into pellets and used as cattle feed, wheatmidds require no preparation, other than to ensure a moisture content ofless than or equal to 15%. Similarly,. soy hulls, the preferred choiceas a bonding agent, are a by product of soybean processing. Usedprimarily as an ingredient in cattle feed, soy hulls require nopreparation. Following a customer order 44, the shelled corn must betested for moisture quantity immediately prior to being ground 46. Asmentioned previously, the moisture content must not exceed 15% 48. Ifthe moisture content is found to be greater than 15%, the shelled cornis returned to storage where further drying will occur 42. If themoisture content is found to be less than 15%, the shelled corn is thenshipped to the hammer mill where it is ground to particles that do notexceed 3.1 mm in any dimension 50. Preferably, the particles will notexceed 1.5 mm in any dimension. These measurements are determined by thescreen mesh at the hammer mill and represent workable and preferredparticle sizes to ensure pellet integrity.

Following the processing of the shelled corn 50, all ingredients aresent to a grain mixer to ensure uniform consistency of the mixture 52.The mixing process should occur until a uniform mixture of allingredients is evident to those skilled in the art. Once a homogeneousmixture is obtained, the mix is then shipped to a pellet mill 54 wherethe pelleting process is commenced. The ingredients are loaded into thepellet mill where the mixture is heated to a temperature of betweenabout 125.degree. F. to about 225.degree. F., although preferably atabout 125.degree. F. This is accomplished to ensure flowability throughthe die. The pellet mill presses the mixture through a die of diameterranging from about 1.5 mm to about 12.8 mm 56. This process involvesusing a pellet mill instead of an extrusion process, through the scopeof the appended claims should be construed broadly enough to support anysystem capable of pelletizing the aforementioned mixture of ingredients.The final product is then ready to be bagged for shipment to thecustomer 58.

1. An ignitable combustible fuel pellet for generating heat in apellet-burning stove or the like, said fuel pellet comprising thefollowing ingredients: (a) ground shelled corn having a moisture contentof not more than 15 percent by weight of said ground shelled corn andcomprising a range of from about 50 percent to about 75 percent byweight of said fuel pellet; (b) an igniting agent for facilitatingcontinuing combustion of said fuel pellet when said fuel pellet iscombusted in a pellet stove or the like; (c) a bonding agent for bondingsaid ingredients together to form said fuel pellet; and (d) ananti-caking agent for promoting flowability of said ingredients duringthe making of said fuel pellet.
 2. The ignitable combustible fuel pelletof claim 1 wherein: (a) said igniting agent is selected from a groupcomprising wheat midds, barley, oats, wheat, dried distiller grain,speltz, and milo; (b) said bonding agent is selected from a groupcomprising soy hulls, dried distiller grain, and milo; and (c) saidanti-caking agent is selected from a group comprising pulverizedlimestone, dehydrated phosphorous, and crushed egg shells.
 3. Theignitable combustible fuel pellet of claim 1 wherein: (a) said ignitingagent comprises at most about 25 percent by weight of said fuel pellet;(b) said bonding agent comprises at most about 20 percent by weight ofsaid fuel pellet; and (c) said anti-caking agent comprises the balanceof said weight of said fuel pellet and at most 5 percent by weight ofsaid fuel pellet.
 4. The ignitable combustible fuel pellet of claim 1wherein: (a) said igniting agent comprises at least about 12.5 percentby weight of said fuel pellet; (b) said bonding agent comprises at leastabout 12.5 percent by weight of said fuel pellet; and (c) saidanti-caking agent comprises the balance of said weight of said fuelpellet and at most about 5 percent by weight of said fuel pellet.
 5. Theignitable combustible fuel pellet of claim 4 wherein said ground shelledcorn comprises particles of size not to exceed about 3.1 mm in anydimension.
 6. The ignitable combustible fuel pellet of claim 1 wherein:(a) said igniting agent comprises about 25 percent by weight of saidfuel pellet; (b) said bonding agent comprises at most about 20 percentby weight of said fuel pellet; and (c) said anti-caking agent comprisesthe balance of said weight of said fuel pellet and at most 5 percent byweight of said fuel pellet.
 7. The ignitable combustible fuel pellet ofclaim 1 wherein: (a) said igniting agent comprises at most about 25percent by weight of said fuel pellet; (b) said bonding agent comprisesabout 20 percent by weight of said fuel pellet; and (c) said anti-cakingagent comprises the balance of said weight of said fuel pellet and atmost about 5 percent by weight of said fuel pellet.
 8. The ignitablecombustible fuel pellet of claim 1 wherein: (a) said igniting agentcomprises about 25 percent by weight of said fuel pellet and remainssubstantially constant as said percent of said ground shelled corn isincreased in a substantially linear fashion from said about 50 percentto said about 75 percent by weight of said fuel pellet; (b) said bondingagent comprises a range of about 20 percent to about 0 percent by weightof said fuel pellet and decreases in a substantially linear fashion fromsaid about 20 percent to said about 0 percent over a major portion ofsaid range of said ground shelled corn as said percent of ground shelledcorn is increased substantially in a linear fashion from said about 50percent to said about 75 percent by weight of said fuel pellet; and (c)said anti-caking agent comprises a range of about 7.5 percent to about 0percent by weight of said fuel pellet and remains substantially constantover a major portion of said range of said ground shelled corn as saidpercent of said ground shelled corn is increased in a substantiallylinear fashion from said about 50 percent to said about 75 percent byweight of said fuel pellet, said percent of said anti-caking agentdecreasing in a substantially linear fashion to said 0 percent beyondsaid major portion.
 9. The ignitable combustible fuel pellet of claim 8wherein: (a) said igniting agent is selected from a group comprisingwheat midds, barley, oats, wheat, dried distiller grain, speltz, andmilo; (b) said bonding agent is selected from a group comprising soyhulls, dried distiller grain, and milo; and (c) said anti-caking agentis selected from a group comprising pulverized limestone, dehydratedphosphorous, and crushed egg shells.
 10. The ignitable combustible fuelpellet of claim 1 wherein: (a) said igniting agent comprises a range ofabout 25 percent to about 0 percent by weight of said fuel pellet anddecreases in a substantially linear fashion from said about 25 percentto said about 0 percent as said percent of said ground shelled corn isincreased substantially in a linear fashion from said about 50 percentto said about 75 percent by weight of said fuel pellet; (b) said bondingagent comprises about 20 percent by weight of said fuel pellet andremains substantially constant as said percent of ground shelled corn isincreased in a substantially linear fashion from said about 50 percentto said about 75 percent by weight of said fuel pellet; and (c) saidanti-caking agent comprises about 7.5 percent by weight of said fuelpellet and remains substantially constant as said percent of said groundshelled corn is increased in a substantially linear fashion from saidabout 50 percent to said about 75 percent by weight of said fuel pellet.11. The ignitable combustible fuel pellet of claim 10 wherein: (a) saidigniting agent is selected from a group comprising wheat midds, barley,oats, wheat, dried distiller grain, speltz, and milo; (b) said bondingagent is selected from a group comprising soy hulls, dried distillergrain, and milo; and (c) said anti-caking agent is selected from a groupcomprising pulverized limestone, dehydrated phosphorous, and crushed eggshells.
 12. The ignitable combustible fuel pellet of claim 1 wherein:(a) said igniting agent comprises a range of about 25 percent to about12.5 percent by weight of said fuel pellet and decreases in asubstantially linear fashion from said about 25 percent to said about12.5 percent as said percent of said ground shelled corn is increased ina substantially linear fashion from said about 50 percent to said about75 percent by weight of said fuel pellet; (b) said bonding agentcomprises a range of about 25 percent to about 12.5 percent by weight ofsaid fuel pellet and decreases in a substantially linear fashion fromsaid about 25 percent to said about 12.5 percent as said percent ofground shelled corn is increased in a substantially linear fashion fromsaid about 50 percent to said about 75 percent by weight of said fuelpellet; and (c) said anti-caking agent comprises about 0 percent byweight of said fuel pellet as said percent of ground shelled corn isincreased in a substantially linear fashion from said about 50 percentto said about 75 percent by weight of said fuel pellet.
 13. Theignitable combustible fuel pellet of claim 12 wherein: (a) said ignitingagent is selected from a group comprising wheat midds, barley, oats,wheat, dried distiller grain, speltz, and milo; (b) said bonding agentis selected from a group comprising soy hulls, dried distiller grain,and milo; and (c) said anti-caking agent is selected from a groupcomprising pulverized limestone, dehydrated phosphorous, and crushed eggshells.
 14. The ignitable combustible fuel pellet of claim 1 wherein:(a) said igniting agent comprises a range of about 25 percent to about12.5 percent by weight of said fuel pellet and decreases in asubstantially linear fashion from said about 25 percent to said about12.5 percent as said percent of said ground shelled corn is increased ina substantially linear fashion from said about 50 percent to said about75 percent by weight of said fuel pellet; (b) said bonding agentcomprises a range of about 20 percent to about 7.5 percent by weight ofsaid fuel pellet and decreases in a substantially linear fashion fromsaid about 20 percent to said about 7.5 percent as said percent ofground shelled corn is increased in a substantially linear fashion fromsaid about 50 percent to said about 75 percent by weight of said fuelpellet; and (c) said anti-caking agent comprises about 5 percent byweight of said fuel pellet and remains substantially constant as saidpercent of said ground shelled corn is increased in a substantiallylinear fashion from said about 50 percent to said about 75 percent byweight Of said fuel pellet.
 15. The ignitable combustible fuel pellet ofclaim 14 wherein: (a) said igniting agent is selected from a groupcomprising wheat midds, barley, oats, wheat, dried distiller grain,speltz, and milo; (b) said bonding agent is selected from a groupcomprising soy hulls, dried distiller grain, and milo; and (c) saidanti-caking agent is selected from a group comprising pulverizedlimestone, dehydrated phosphorous, and crushed egg shells.
 16. Anignitable combustible fuel pellet for generating heat in apellet-burning stove or the like, said fuel pellet comprising thefollowing ingredients: (a) grade 2 fine ground shelled corn having amoisture content of not more than about 15 percent by weight andcomprising about 50 percent by weight of said fuel pellet; (b) soy hullsas an igniting agent for facilitating continuing combustion of said fuelpellet when said fuel pellet is combusted in a pellet stove or the like,said soy hulls comprising about 20 percent by weight of said fuelpellet; (c) wheat midds as a bonding agent for bonding said ingredientstogether to form said fuel pellet, said wheat midds comprising about 25percent by weight of said fuel pellet; and (d) pulverized limestone asan anti-caking agent for promoting flowability of said ingredientsduring the making of said fuel pellet, said anti-caking agent comprisingabout 5 percent by weight of said fuel pellet.
 17. The ignitablecombustible fuel pellet of claim 16 wherein said ground shelled corncomprises particles of size not to exceed about 3.1 mm in any dimension.18. A method for forming ignitable combustible fuel pellets forgenerating heat in a pellet-burning stove or the like, said methodcomprising the steps of: (a) grinding in a hammer mill shelled cornhaving a moisture content of not more than about 15% by weight; (b)mixing said shelled corn ground in said grinding mill with otheringredients in a grain mixer to provide a ground shelled corn mixturewherein said shelled corn comprises a range of from about 50 percent toabout 75 percent by weight of said ground shelled corn mixture; and (c)pressing said ground shelled corn mixture in a pellet mill having a dieof size in the range of about 1.5 mm to about 12.8 mm at a temperaturein the range of about 125 degrees Fahrenheit to about 225 degreesFahrenheit to form said combustible fuel pellets.
 19. The method ofclaim 18 wherein said pressing step is accomplished at a temperature ofabout 176 degrees Fahrenheit.
 20. The method of claim 18 wherein saidshelled corn is ground in said hammer mill into particles of size not toexceed about 3.1 mm in any dimension.